Explanation

Soil colloids are generally classified into three main types: mineral (inorganic) colloids, organic colloids, and organo-mineral complexes. However, in many agricultural and soil science contexts, especially in simplified classifications or specific textbooks used in Pakistan's curriculum, they are often categorized into two primary groups: clay minerals (mineral colloids) and humus (organic colloids). Wait, let me double-check standard soil science. Standard classification is usually 3 types: Clay minerals, Humus, and Organomineral complexes. But sometimes it's simplified to just Mineral and Organic. Let's look at the options: 4, 2, 6, 5. If the standard is 3, none match perfectly. However, many sources classify soil colloids into two main types: Inorganic (mineral) and Organic. This fits option B. But wait, some classifications might list more. Let's check common MCQs for this topic. Often, questions ask about the number of *types* of clay minerals or something similar. If the question is